One voice wearing too many hats

It always sounds peculiar to me to hear a live DJ go to a break and then immediately play one or more commercials featuring his or her own voice.  When I hear a DJ say, "I'll be right back," then play a commercial (s)he recorded for an auto parts shop, a station promo, a commercial for a florist, and then a PSA about the health risks of smoking, I think, "Are there no other smooth voices in this town?  It's like saying, 'I'll be right back,' followed by, 'Actually, here I am again.'"